powder laundry soap verses Borax

[loader]

What can I do to fix the ingots I made with fluxing with the Borax? Will the sawdust bring tin out of suspension?

Geargnaher said...........

No, once the tin gets sucked up by the borax, it's gone. Probably not anywhere near all of your tin was trapped by the borax, so don't worry too much about it, but some was lost to be sure. Just add a half-percent back and you should be fine.

Ok... first off thank you all for spending the time to help me to try to understand the chemistry behind fluxing. Even though I do pluming and use flux, I don't understand the chemical reaction of fluxing...LOL Anyway..... I do know that it cleans and allows the solder to flow and in casting the TIN aids in flowing.

So in the gist all isn't lost when I used borax. Now... according to geargnasher, not all the tin is was trapped in the borax so I can add back some tin....1/2%?? If I use lead free plumbers solder it consists of 95% tin 5% antimony... that's a pound spool. 1/2%.... what's 1/2%? Lyman says #2 alloy is 18 pounds lead, 1 pound tin, and 1 pound antimony... that I can relate too.. but 1/2%? Care to tell me if I have a pot full of lead say 18 pounds... of 18 pounds how much is 1/2% tin that I need to add?

[randyrat]

First, try to cast with your alloy. If it cast well, nice boolits don't worry about adding any Tin.

I only add Tin when I have problems casting nice filled out boolits.
Most the time it's a temperature problem or contamination problem in the mold cavities that hinders casting
OR
I add Tin to lighten n a particular boolit a tad...ie- Boolit is cating 243 grains and I want 240 grain boolits. By adding some Tin my boolits will be closer to 240 gains. Tin will also toughen without the brittleness or Antimony.

I also use sawdust

[milprileb]

Moving my question to a separate thread so as not to confuse the OP original focus.

[cbrick]

of 18 pounds how much is 1/2% tin that I need to add?

5 3/4 ounces.

randyrat is correct, its not mandatory to add tin. Many people do, I do. If your going to add tin to a Pb/Sb alloy keep the Sn percentage at or below the Sb percentage.

To figure out the tin percentage I do this.

18 pounds lead X 7000 grains (there is 7000 gr in a pound) = 126000 gr. and 2% of 126000 is 2520 gr. The formula for converting grains to ounces is .00229 so multiplying 2520 grains by .00229 gives you 5.7708 or 5 3/4 ounces.

I convert to ounces because I weigh my ingots and tin on a postal scale that weighs in ounces.

Rick

[loader]

thanks Rick.... appreciate it. I have .00218 on my scale for 1 ounce... 5.5 or 5.75 whatever...LOL

[skeet1]

I thought that saw dust could not possibly work but the cost was inviting so I tried it. It works great and I wouldn't use anything else. Compared to using bullet lube in the pot and making nauseous smoke, the wood smoke is not near so bad. You can also ignite the sawdust just like you did the bullet lube with a lighter once it starts to smoke.

Ken

[runfiverun]

this thread brought a tear to my eyes......
just so's you all know.
remember that the saw dust is half of the equasion.
you also need a oxygen free barrier for it to work.
hence the fire.
i use the saw dust, and old candles or failed flux.
in the garage plain sawdust on top of the mix [and yes sometimes marvelux I hate it but it's a trade off. i would rather lose the small amount to the borax than the big amount to the air]
iv'e tried the kitty litter, and it does work as a heat barrier,and maybe possibly a fluxing agent once it breaks down [doubt it though]

[nanuk]

for sawdust, grab a chainsaw and an old log.... make your own

I've even read somewhere folks put oil or melted wax in with the sawdust to cover both bases at once.

[cbrick]

I've even read somewhere folks put oil or melted wax in with the sawdust to cover both bases at once.

When using the sawdust what is it the oil or wax supposed to do?

Rick

[plainsman456]

And you do not need to sit over the pot when waiting for the sawdust to burn down.
Sometimes I think folks don't use enough sawdust when smelting or casting.

[geargnasher]

When using the sawdust what is it the oil or wax supposed to do?

Rick

It provides extra, more volatile hydrocarbons to be oxidized (combusted) near the surface of the melt, and provide a very high carbon monoxide enviroment at the surface, which accelerates the reduction process. Basically adding wax/oil to the sawdust is like adding bleach to your laundry along with the detergent, a little extra "kick".

In order for reduction to occur, oxidation must occur also simultaneously. The hydrocarbons are oxidized while the elemental metals are reduced. Oxidation is enhanced by burning hydrocarbons, and grease/oil/wax burns a little better than sawdust at 650 degrees, so it enhances reduction.

When I smelt dirty scrap, I pour a cup of diesel oil on top of the mess when I light the pot, the resulting smoky, sooty, poorly-burning flame makes lots of carbon soot and carbon monoxide which is a fantastic enviroment in which to melt lead. It reduces oxides constantly while the scrap melts, and consumes almost all of the oxygen in and around the pot, preventing further oxidation while melting. It also adds BTUs to the lead from the top, and speeds the smelting process while saving a lot of propane. Once I skim the junk, I use sawdust and a large stick to stir, scrape, and FLUX the remaining suspended junk and contaminant elements out of the melt.

Since I started using Glen Fryxell's tips on fluxing, my boolits have improved. I was able to get very clean lead before, but it seems that the sawdust removes stuff that can't be seen and is a hindrance to casting. Aluminum and calcium are a couple of common contaminants in WW that are removed with sawdust, and muck up fillout when casting.

Gear

[nanuk]

yeah... kinda what Gear said
I wish I could remember the post about oily sawdust.
IIRC, the idea was the sawdust helps clean the dirt and crud, and the wax/oil helps the charred wood reduce the metals back in from the clips and crud that float to the top....

[loader]

Fryxell doesn't mention diesel fuel, but I see the process.... carbon, which wood has after burned. In a pinch charcoal would be the same.... and anything that has carbon.

Looks like sawdust accomplishes it all and it's free!!!.... removes impurities, reduces tin (which aids in casting mold fillout), and protects against oxidation.

Guess my next question would be is, how much sawdust is needed for how much melt?

[alamogunr]

Every so often I go to the local lumberyard(owned by a friend) and get an ice cream bucket full of sawdust. I'm sure it is 90% pine. I create quite a bit of sawdust in my shop but I vacuum it up along with just about everything else that I make a mess with. It is too easy to get clean sawdust to bother with whatever is in the shop vac container.

John
W.TN

PS if anyone wants a can of Marvelux, they can have it for postage.

[rintinglen]

In smelting ingots from dirty metals, primarily range scrap and wheel weights I formerly used old motor oil. I have since abandoned that practice, but it worked very well. A half cup added to a forty pound 10" skillet of melt and immediately ignited added heat to the melt, reduced oxides, and initially made a dense black cloud that vaguely resembled a burning tire. Not everything that works is a good idea. Now I use sawdust for ingots and candle wax in my pot.

[cbrick]

Now I use sawdust for ingots and candle wax in my pot.

The sawdust used when making ingots will remove possible contaminates such as aluminum, calcium, zinc etc. It’s fairly doubtful though that a single fluxing will remove all possible contaminants in the alloy, a great start of course but additional fluxing as in the casting pot will remove more of any that may remain.

By using the wax in the casting pot you’re missing out on the opportunity to remove more of any possible contaminants. The wax will not, cannot remove these contaminants, reduce tin yes, remove any remaining contaminants, no.

So I just have to ask, why not use the sawdust in the casting pot as well?

PS if anyone wants a can of Marvelux, they can have it for postage.

Geez, if I still had any Marvacrap around here I would be willing to pay the postage, cheap way to be rid of that horrid stuff.

Rick

[cbrick]

Guess my next question would be is, how much sawdust is needed for how much melt?

I use about 3/4 to 1 inch on top of the pot, enough so that when it's burnt to ash there is enough ash to completely cover the top of the melt.

Rick

[Ozarklongshot]

Ok Now I have learned more than I know what to do with. All great info. I have never lit the pot. My BP pot is in the shop part of the house. Exhaust fans suck all smoke out and heat out. Not sure how that would work with fire. I will start cleaning my WW and junk outside now and will try the sawdust. That many people can't be wrong. Also thanks for the links, more good edumacation for this ole hillbilly

[cajun shooter]

I just wanted to say that if any of you gather up saw dust from Home Depot or Lowe's or any other type of store that cuts wood for the customers, be careful. If any treated lumber is cut then that sawdust contains toxic type of materials. We had some guys that were new on a job that built a fire to keep warm. They had the fire in a 55 gallon drum and were standing around it. Several had to go to the hospital with problems from inhaling the fumes. Pat Marlin of this forum has a wood shaving that he sells for $20 a box to your door. I have been using it for over three years with great results. Not only is it a great flux but it has a very pleasant smell that my wife loves and that is a big plus. After I finish my flux, I add another pinch to cover the alloy in my pot and leave it. This gives the room a pleasant odor.

[Longwood]

I have been casting since back in the 70's.
The use of sawdust for fluxing is one of the very best tips I have learned on this site.
I use pellet stove pellets.
I wet a few and then let them dry before use in my pots.
A 40 pound $5 bag will turn into about four bags of fine chips that will last many, many years.